It is not 100 percent clear who is responsible for an underground diesel spill by the Sterling Highway in Soldotna, but for now, Unocal is paying the cleanup costs.
According to the Alaska Department of Environmental Conservation, Unocal formerly owned a tank farm at the site, which now is a vacant lot between Odie's and C&M Muffler on the Sterling Highway.
Scott Widness of Geo Engineers in Anchorage is overseeing the excavation for Unocal's asset management group in Edmonds, Wash. He said he expects the contractor, L&J Enterprises of Nikiski, to excavate roughly 800 cubic yards -- about 80 dump truck loads -- of diesel-contaminated soil.
Don Seagren, DEC environmental specialist, said that will go to Alaska Soil Recycling in Anchorage, which will run it through an incinerator to burn off diesel and other contaminants. Unocal plans to fill the hole with clean soil, he said. After that, DEC will watch monitoring wells on the property for signs of additional contamination and decide what else must be done before it authorizes an end to the cleanup.
"This isn't going to close out the site," Seagren said.
According to a risk assessment Unocal filed with DEC, the tank farm operated from 1959 to 1977. The first recorded owner was Howard Binkley, who acquired it as part of a homestead. Burton Carver acquired it in 1961, and Alaska Oil Sales and Service became part-owner later that year.
In 1962, Union Oil Co. of California, now doing business as Unocal, became the owner. In 1975, the property went to Don Bailey Inc. In 1977, the owner was listed as Earl Billingslea, president of Don Bailey Inc. Billingslea formed Alaska Oil Sales, which had no relation to Alaska Oil Sales and Service. Mark Brearley, senior staff geologist for Unocal's asset management group in Edmonds, said the tank farm was operated for some time by Unocal consignees.
It was dismantled in 1977. Beginning in 1978, the land passed through a series of private owners. Last year, the city of Soldotna took the deed after foreclosing on unpaid property taxes and assessments, said Joel Wilkins, city finance director. She said the previous owner will have to pay $12,000 plus accrued interest to redeem the land.
Brearley said the underground contamination was discovered years ago, when a gas line was installed to an adjoining building. Widness said Unocal has been monitoring and exploring the site for about a decade. The contamination, mainly diesel, appears to have come from a loading rack at the former tank farm, he said.
Seagren said he does not think any contamination has migrated off the property.
"It hasn't gone past the sidewalk," he said. "We have monitoring wells surrounding the site. The groundwater flow is diagonally across the site toward the Blazy Mall. They monitor quarterly."
Air samples in the strip mall that contains Odie's detected no fumes, Seagren said, so he does not believe contamination has migrated under the building, either.
Seagren said Unocal had asked DEC to set cleanup standards based on a risk assessment for the property. The department was reviewing the risk assessment, but about a year ago, a sheen appeared in two of the 13 monitoring wells. That was not part of the risk assessment, he said.
Unocal sent a vacuum truck several times to suck out the problem wells, but that failed to take care of the sheen. Seagren said that led to the decision to excavate. Brearley said excavation was always part of the plan. Seagren said L&J Enterprises will probably excavate to a foot or two below groundwater, then put clean fill in the hole. DEC will watch the monitoring wells for a year to see if the sheen returns.
"If it doesn't, we'll probably go back to reviewing the risk assessment," he said.
Brearley said Unocal has spent a significant sum on monitoring and cleanup.
"We're footing the bill for now," he said. "Whether we look to other parties for partial reimbursement later on is a decision yet to be made."
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